An Illinois’ state climatologist says he believes the worst U.S. drought in decades likely will continue through next year.

The Belleville News-Democrat reports that Jim Angel of the Illinois State Water Survey says “it’s going to be a long, slow recovery from this particular drought.” Angel spoke Thursday during a conference in St. Louis about the Mississippi River’s future.

More than 60 percent of the continental U.S. has been gripped by some form of drought since last summer. More than 90 percent of Nebraska and Oklahoma were hit by extreme or exceptional drought. Those are the two worst classifications.

The drought has withered crops and lowered the Mississippi River’s levels to a point that could force slowdowns, if not shutdowns, of barge traffic between St. Louis and Cairo.